Tire-mold



T. MIDGLEY.

TIRE MOLD.

- APPLICATION FILED OCT. 24. 1918.

1,368,641 Patented Eeb.15,1921.

INV TOR. I M5 ATTORNEYS.

STATES narurri THOMAS MIDGLEY, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO THE FILM RUBBER COMPANY, OF CHICOPEE FALLS, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

aseaeai;

T all'w 710m it may camera:

- common practice to buildup the tire cas ing, or tire, on an annular core or mandrel from layers of fabric and rubber, andwhen the tire has been built up to insert.

Be it known that I, 'THoMAs Minster, a citizen of the UnitedStates of. America, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented certain new and useful Improve mentsin Tire-lilolds, of which the following is a specification;

My invention relates to molds and more particularly to a tire mold;

In the building of rubber tires it is the it in a mold and vulcanize it, the tire being suitably-supported interiorly, as upon the core upon which it was built up. .The tires have a base at each side of them to aid in fastening them on the wheel rim and it is common to place endless bead wires of fixed diameter in these bases. Now, it is desirable to place layers of fabric beneath the bead wires, 2'. 6., radially below them. But if a sufficiently few layers of this fabric are used to permit the easy insertion of the tire in the mold, such a number is insufficient to give aproper base, while if suflicient layers to given proper base are used then this number of layers must, to insert it in the mold, be forced or compressed radially outwardly, since it is, before compression, considerably thicker through, radially, than the space feasible to provide in the mold to accommodate it. Again, compression of the fabric radially one layer against the next is I highly desirable in itself. Because of this need for compression, it is no small difiiculty to get a tire with a proper number of layers into the mold, for the fabric has to be pressed down and jammed into place as best the workman can. It can well be understood that the jamming of the fabric into place is many times most unsatisfactorily done, with the result that the tire comes out of the mold with imperfect bottoms to its bases and has to be sold as asecond.

It has, I am aware, been previously proposed to use a mold with rings of fixed diameter, designed to be placed on clencher tire beads and then slid sidewise in the mold proper to compress the beads sidewise. But these rings, since they slid sidewise, served merely to compress the beads sidewise, serving, perhaps, to compact them sidewise but,

erally upon devices of the character TIRE-MOLD.

bpecificetion of LettersPatent. Pmiyggfiggdl Hugh, 15, 1921,

AppIication filed October 24, 1916. Serial No. 259,498.

- not for any practical purpose, serving to just as in a simple mold, there was the great difficulty of having to pack, jam and compress a head into the receptacles or else have lnsuiiicient layers at the bottom of the bead. Briefly, there were no provisions made for putting as many base layers on as desired, readily compressing them radially,

and then slipping the tire into the mold.

Now, I have devised a mold which, while permitting the use of the large and desirable number of layers, and the desirable radial compression, obviates this trouble of difhcult and unsatisfactory insertion into the mold or into receptacle-form rings, to which I have called attention. The use of this mold enables tires with perfectly molded bases to be produced unfailingly and with none of the difficulty above referred to.

, One object of my invention is to provide a tire mold enabling the production of tires with perfectly molded bases.

Another object is to provide a mold into which a, tire, havin bases oversize before insertion in the mold: can be inserted easily,

properly, and expeditiously by inexpert labor.

Another object is to provide a mold into which a tire, having a desirable number of layers of material at thebottoms of its bases, can be easily and accurately inserted,

and the material properly compressed.

To these ends, and also to improve gleni dicated, my invention consists in the following matters hereinafter described and claimed.

In the accompanying drawings:

Figure 1 is a radial cross-section of a mold embodying my invention;

Fig. 2 is a fragmentalview of the mating ends of one of the compressor mugs of the illustrated mold and Fig. 3 is a side elevation of a tire or cas mg with one of the compressor rings sprung out of shape and just beingplaced on the tire base. 4

Without restricting my invention thereto,

The preferably metallic mold, indicated i out its length except, preferably, for a single generally by the character 1, comprises two separable matched and like annular halves 2 and 3., providing, when assembled, the

- annular space 4 for receiving the tire T to bevulcanized. A core or mandrel M, w1th.

in the tire, exemplifies means forcarrying and supporting the tire. Each mold-half is provided, just below (radially) the position which the base B of the tire occupies, with an annular recess 5. A preferably metallic spring ring 6 continuous throughcutting thereacross, is receivable. in each recess 5. The top, or'radially outer, face 7 of sirably, the natural unsprung diameter of a the ring is slightly less than the diameter such ring is contoured to properly shape the bottom of the base, being flat in the present instance. The lower,'or-radially inner, face 8 of such ring is so contoured, and the corresponding face 9 of the recess' 5 is so correspondingly contoured, that the rings 6 will reac ily slide into place and properly center, thus to properly locate the tire in the mold. As here illustrated, the faces 8 and 9 are shown as inclined planes slopingdownward in the direction of approach of the mold-halves and forming a" species of cooperating centering-cones.

. The compressor rings 6 are separable from the mold proper in order that they can be bodily removed therefrom and applied to the tire before its introduction to the mold proper, as. indicated in Fig. 3. Because of the spring character of each ring, it can be deformed, as into the position indicated in Fig. 3, and fitted to the bottom of the base.

Now the ring is of such dimensions that when it is in it's normal condition l. 0.. its condition hen its ends are closely mated as indicated in Fig. 2, its diameter corresponds to the diameterof the base after the proper compression of the desirable number of layers of fabric 10, and gives a base of standard diameter. The act of placing the ring in position performs the desired cornpression of the layers. And the normal inside diameter of the ring is 'such as to adapt it to slide readily into the mold proper. De-

of the ring when its ends are mated, whereby the ring, when its ends have been mated, re-.

' is placed in the mold proper. And this opcration is performed without difficulty, since the bases are already compressed and the rings are of the right diameter to fit accurately into the mold proper; It, will be noted, too, that the rings, a plied and dimensioned as described, give t e bases afixed and accurately determined diameter.

Should there be any sticking of the rings upon their introduction into the mold pro-per, then, when the mold-halves are forced together by external pressure, as by bolts 11, as shown in'Fig. 1, any tendency of the rings to stick and so shift sidewise with the mold-halves instead of sliding into place is desirably resisted by a. suitable abutment, as the molds annular T-ring 12.; It

will be understood that this action is not designed to be sufficiently severe to expand the rings-the ends of the rings remain closely fitted together thereby to obviate the formation of a ridge or the like on the bottom of the bead, such as might be formed did the. ends separate. V

With the illustrated structure: the fabric elements 10, of .the desired large number of layers, can be fitted accurately, evenly, quickly, and without creases or yvrinkles against the parts of the mold which they contact, 2'. e. the rings 6 and, so, intothe mold proper.

to the evenly, uniformly, and accurately directly,

bottoms of the fabric and is exerte uniformly, and radially outward 1n the.

ideal manner. When the tire is removed from the mold the tire comes away from the mold proper easily, since, should there be any sticking of the bases, it will be to the compressor rings and, the rings coming out with the tire, they can thenbe easily reticiilarly in Fig. 2, I form the matching 'cnds of each ring 6 'V-shap'ed in order to insure one end acting asa catch for the other,

keeping the ends in alinement.

"moved from the "bases by deforming therin 's. w l losirably, and as illustrated more par-, I

It will be seen thatl have provided .a

mold providing for the readyand'accurate insertion of tires having the desired large number of fabric layers at the bottom of their bases and with said bases oversize prior to the lllSGItlOIl' of the tire in the mold; providing for the accurate compression of the said oversize bases, particularly by pressure applied directly to the faces of the bottoms, and providing, generally, for

the inexpensive and ready production of standard diameter tires having a relatively large number of layers of compressed fabric at the bottoms of their bases. T

What I claim is',

1. In a tire mold, apair of mated annular sections together presenting a cavity to receive a tire, said cavity extending slightlyv beyond the base of the tire, and aflording space under the base forthe reception pf it compressor ring, an annular flange forming part of each mold section and extendingiun- 90 I When the compacting pressure is applied to the fabric, it is applied.

der the base of the tire so as to contact with the internal circumference of the compressor ring, and a compressor ring adapted to be expanded to compress the base of the tire andto lie snugly in the space between the said base and the walls of said cavity.

2. In a tire mold, a pair of mated annular sections together presenting a cavity to receive a tire, said cavity extending slightly beyond the bases of the tire, and affording space under each base for the reception of a compressor ring, an annular flange forming part of each mold section and extending under the base of the tire so as to contact with the internal circumference of the compressor ring, and a pair of split compres-' sor rings adapted to be expanded to compress the bases of the tire and being each constructed to maintain itself in its expanded condition by the interlocking of its split ends, 'said compressor rings lying in the spaces between the said bases and the Walls of said cavity;

THOMAS MIDGLEY. 

